Aim. We present the medium-term clinical results of a reverse total shoulder arthroplasty with a trabecular metal glenoid base plate. Patients and Methods. We reviewed 125 consecutive primary reverse total shoulder arthroplasties (RTSA) implanted in 124 patients for rotator cuff arthropathy. There were 100 women and 24 men in the study group with a mean age of 76 years (58 to 89). The mean follow-up was 32 months (24 to 60). No patient was lost to follow-up. Results. There were statistically significant improvements in the mean range of movement and Oxford Shoulder Score (p < 0.001). Kaplan-Meier survivorship at five years was 96.7% (95% confidence interval 91.5 to 98.7) with aseptic glenoid failure as the end point. . Radiologically, 63 shoulders (50.4%) showed no evidence of notching, 51 (40.8%) had grade 1 notching, ten (8.0%) had grade 2 notching and one (0.8%) had grade 4 notching. Radiolucency around the glenoid base plate was found in one patient (0.8%) and around the humeral stem in five (4.0%). In all, three RTSA (2.4%) underwent revision surgery for aseptic mechanical failure of the glenoid within 11 months of surgery due to malseating of the glenosphere. Conclusion. The clinical results of this large independent single unit series are comparable to those from previous series of RTSA reported in the literature. A trabecular metal base plate is safe and effective in the medium-term. Cite this article: Bone Joint J 2016;98-B:969–75

Aims. The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky IIIA and IIIB defects. Patients and Methods. A retrospective study was conducted at four centres between August 2008 and January 2015. Patients treated with TM augments and TM shell for a Paprosky grade IIIA or IIIB defect, in the absence of pelvic discontinuity, and who underwent revision hip arthroplasty with the use of TM augments were included in the study. A total of 41 patients with minimum follow-up of two years were included and evaluated using intention-to-treat analysis. Results. There were 36 (87.8%) patients with a Paprosky IIIA defect and five (12.2%) patients with a Paprosky IIIB defect. The mean age was 56.7 years (28 to 94). There were 21 (51.2%) women and 20 (48.8%) men. The mean follow-up was 39.4 months (12 to 96). One (2%) patient died after eight years. No failures were noted in the series. The mean survivorship was 100% at the time of latest follow-up. Conclusion. The results of this multicentre study showed encouraging short- and mid-term results for the use of TM augments in the management of Paprosky grade IIIA and IIIB defects. Cite this article: Bone Joint J 2018;100-B:903–8

Trabecular metal (TM) augments are a relatively new option for reconstructing segmental bone loss during acetabular revision. We studied 34 failed hip replacements in 34 patients that were revised between October 2003 and March 2010 using a TM acetabular shell and one or two augments. The mean age of the patients at the time of surgery was 69.3 years (46 to 86) and the mean follow-up was 64.5 months (27 to 107). In all, 18 patients had a minor column defect, 14 had a major column defect, and two were associated with pelvic discontinuity. The hip centre of rotation was restored in 27 patients (79.4%). The Oxford hip score increased from a mean of 15.4 points (6 to 25) before revision to a mean of 37.7 (29 to 47) at the final follow-up. There were three aseptic loosenings of the construct, two of them in the patients with pelvic discontinuity. One septic loosening also occurred in a patient who had previously had an infected hip replacement. The augments remained stable in two of the failed hips. Whenever there was a loose acetabular component in contact with a stable augment, progressive metal debris shedding was evident on the serial radiographs. Complications included another deep infection treated without revision surgery. Good clinical and radiological results can be expected for bone-deficient acetabula treated by a TM cup and augment, but for pelvic discontinuities this might not be a reliable option. Cite this article: Bone Joint J 2013;95-B:166–72

Shoulder arthroplasty has experienced exponential growth in the past 10–15 years, largely due to improvements in anatomical design, increased application of technology to address various clinical pathology, and improved access to experienced shoulder surgeons. Glenohumeral arthritis has historically been the most common indication for a shoulder replacement, and glenoid wear has been the main concern with regards to longevity of the prosthesis. Attempts to improve glenoid components involve alterations in peg or keel configuration, as well as the introduction of metal backed constructs. Early experience with metal backed components led to very poor results with often catastrophic loosening and destruction of glenoid bone. Proximal humerus fractures are another common indication for a shoulder arthroplasty, and in these cases, tuberosity fixation and healing are the challenge precluding a consistently successful result. More recently, base plate fixation in the setting of a reverse shoulder arthroplasty has come to the forefront as a significant factor. Trabecular metal technology has emerged as a compelling method of enabling powerful bone ingrowth to the surfaces of arthroplasty components. Trabecular metal is composed of tantalum. It is used to form a carbon scaffold which has a modulus between that of cancellous and cortical bone, thus has some flexibility when made into an independent construct. Vapor deposition onto arthroplasty surfaces provides a bone ingrowth surface. There is interest in utilizing trabecular metal for glenoid and tuberosity fixation in particular. Trabecular metal proximal coated stems provide an ingrowth surface for tuberosity fixation in the setting of proximal humerus fractures. Long term results are still pending. Because the metal is much less stiff then other metals, trabecular metal has recently been used along the back of polyethylene glenoids. The original design had a problem with fracture at the base of the pegs. A redesigned component instituting a cruciate design was implemented, and is currently available on a limited release basis with promising early results. The use of trabecular metal on the deep surface of the reverse arthroplasty baseplate and the proximal aspect of the reverse stem has led to successful fixation, allowing cementless fixation of both the humeral and glenoid components. Learning objectives of this presentation include:. Understand the mechanical characteristics of trabecular metal and its bone ingrowth characteristics. Familiarize with currently available prosthetics incorporating trabecular metal technology. Case presentations utilizing trabecular metal coated components

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique: The acetabular bed is prepared. If there is less medial bone stock than 2 mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilization, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a trabecular metal cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There has been 4 cup loosenings with 3 re-revisions

Purpose. The aim of this study was to compare the clinical outcomes of the revision TKA in which trabecular metal cones and femoral head allografts were used for large bone defect. Method. Total 53 patients who have undergone revision TKA from July 2013 to March 2017 were enrolled in this study. Among them, 24 patients used trabecular metal cones, and 29 patients used femoral head allografts for large bone defect. There were 3 males and 21 females in the metal cone group, while there were 4 males and 25 females in the allograft group. The mean age was 70.2 years (range, 51–80) in the femoral head allograft group, while it was 79.1 years (range, 73–85) in the metal cone group. Bone defect is classified according to the AORI classification and clinical outcomes were evaluated with Visual Analogue Scale (VAS), Hospital Special Surgery-score (HSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and ROM. Operation time was also evaluated. We used radiographs to check complications such as migration or loosening. We took follow-up x-rays and 3D CT of the patients, to assess the mean bone union period. Shapiro-Wilk test was done to check normality and Student T-test and Mann Whitney U-test were done for comparison between two groups. Result. The mean follow-up period was 3 .75 years (Range; 2.1 ∼ 5.75). The pre-op scores did not show significant difference. The mean VAS in the allograft and trabecular metal cone groups was 2.1 ± 0.87 and 1.8 ± 0.53, respectively (p = 0.16). The mean HSS score were 76.3 ± 5.51 and 79.2 ± 4.12 respectively (p = 0.13) and the mean WOMAC scores were 15.1 ± 3.25 and 14.8 ± 3.31 respectively (p = 0.06), and the mean KOOS scores were 27.8 ± 4.77 and 25.5 ± 4.84, respectively (p = 0.07). The mean ROM ranges were 100.6 ± 17.54 and 101.3 ± 19.22, respectively (p = 0.09). But the mean operation time of the allograft and trabecular metal cone groups was 137 minutes (Range; 111–198) and 102minutes (Range; 93 −133) (p=0.02) respectively, which showed statistical significance. In follow-up x-rays, no migration or loosening of the implants, osteolysis and other complications were found in both groups. In follow-up 3D CT, osteointegration was seen at the trabecular metal cone site, host bone being interpreted to the host bone. The allograft group showed fibrous and stable union in follow-up 3D CT. Conclusion. According to this study, in case of revision TKA with large bone defect, using whether allograft or trabecular metal cones did not affect the clinical outcomes. However, operation time was significantly shorter in trabecular metal cone group, therefore, in patients with poor general condition along with severe underlying diseases, usage of trabecular metal cone would be a better choice to shorten operation time and ease postoperative care. Keywords. Revision TKA, metal cone, allograft, bone defect. For any figures or tables, please contact authors directly

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique: The acetabular bed is prepared. If there is less medial bone stock than 2mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilisation, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a trabecular metal cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There have been 4 cup loosenings with 3 re-revisions

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique: The acetabular bed is prepared. If there is less medial bone stock than 2 mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilization, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a trabecular metal cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There has been 4 cup loosenings with 3 re-revisions. Our most up to date data is 101 cases with an average follow-up of 3 years. There has been one infection that underwent a two stage revision. There are 4 loose cups – 3 revised

We compared the performance of uncemented trabecular metal tibial components in total knee replacement with that of cemented tibial components in patients younger than 60 years over two years using radiostereophotogrammetric analysis (RSA). A total of 22 consecutive patients (mean age 53 years, 33 to 59, 26 knees) received an uncemented NexGen trabecular metal cruciate-retaining monobloc tibial component and 19 (mean 53 years, 44 to 59, 21 knees) a cemented NexGen Option cruciate-retaining modular tibial component. All the trabecular metal components migrated during the initial three months and then stabilised. The exception was external rotation, which did not stabilise until 12 months. Unlike conventional metal-backed implants which displayed a tilting migration comprising subsidence and lift-off from the tibial tray, most of the trabecular metal components showed subsidence only, probably due to the elasticity of the implant. This pattern of subsidence is regarded as being beneficial for uncemented fixation

The indications for cementless acetabular fixation have been broadened because our data supports the use of trabecular metal cups even when there's limited bleeding host bone contact. Trabecular metal augments have allowed us to use cementless cups when there is segmental loss of bone. Surgical Technique:. The acetabular bed is prepared. If there is less medial bone stock than 2mm, then morselised allograft is impacted by reverse reaming. When reaming is complete and less than 50% bleeding host bone is available for cup stabilization, then a trabecular metal cup is indicated. Trabecular augments are used if the trabecular cup trial is not stable, or if it is uncovered by 40% or more. The conventional augments come in different sizes to accommodate the diameter of the cup and the size of the defect. Larger defects are addressed with anterior and posterior column augments, and superior defects with figure of seven augments. Augments are fixed with at least two screws. The interface between the cup and the augments should be stable, but some surgeons place a very thin layer of cement between the augment and cup so micromotion does not occur while ingrowth is occurring. We have used trabecular metal augments in 46 acetabular revisions in conjunction with a TM cup. Thirty-four cases have at least 2 years follow-up with an average of 64.5 months. There has been 4 cup loosenings with 3 re-revisions

The authors studied the short-term results following patellar resurfacing using trabecular metal patella. Ten patients underwent primary (2 cases) or revision (8 cases) TKA with the use of a trabecular metal patella and were evaluated at a mean follow-up of 24 months. All patients had marked patellar bone deficiency or patellar absence precluding resurfacing with a standard cemented patellar button. The all polyethylene patella was cemented into the trabecular metal base and the remaining patella bone stock; additional fixation was provided by non-adsorbable sutures through the peripheral holes on the metal shell. No intraoperative complications occurred. There was no displacement of any trabecular metal patellar component and no patellar fractures. The fixation appeared excellent at three to six months radiographic evaluation with uniform bone contact in the peripheral regions in both lateral an Merchant radiographic views. The mean Knee Society scores improved in all patients

Purpose. A Trabecular Metal Modular Acetabular System (Zimmer, Warsaw, Indiana, USA) is a peripheral rim expansion (elliptical) cup, i.e. a non-hemispherical cup. Radiologically a non-hemispherical cup may be deferent from other conventional hemispherical cups. We reviewed radiological findings of a Trabecular Metal Modular Acetabular System chronologically. Methods. Twenty six patients with osteoarthritis underwent primary total hip arthroplasty (THA) using a Trabecular Metal Modular Acetabular System from 2011 to April 2013. Twenty five patients (follow-up rate: 96.2%) 31 hips could be followed-up over a year were registered. In common, the diameter of every femoral head was 32 mm. We planned the acetabular cup inclination angle to be 45-degree, the cup coverage with host-bone (cup-CE angle) to be over 10-degree, and high hip center was allowed up to 20mm. In case of the cup-CE angle under 10-degree, an acetabular cup was placed medially using Dorr's medial protrusio technique. We established the medial protrusion angle indicating the degree of medial protrusion of an acetabular cup over the pelvic internal wall. The medial protrusion angle was defined by the center point of THA (C) and the 2 cross-points (X. 1. , X. 2. ) which the outline of an acetabular cup crosses the Kohler's line (Figure 1). The cup anteversion angle was measured by the method of Lewinnek, and the cup fixation was evaluated according to the Tompkin's classification. Results. The average follow-up period was 1 year and 3 months (1y1m to 2y8m). The mean diameter of the cup was 54 (48 to 56) mm. Seven high-hip center joints were recognized (2 to 11 mm). The average of cup inclination angle was 42 (32 to 52) degree, of cup anteversion angle was 14 (5 to 36) degree, and of cup CE angle was 25 (−14 to 45) degree. Dorr's medial protrusio technique was necessary in 18 hips. In these 18 hips, the average of medial protrusion angle was 57 (24 to 70) degree. In 4 hips of cup-CE angle less than 10 degree, acetabular bulky bone graft was added. All 31 hips showed the stable fixation, even in 18 hips undergone medial protrusio technique. There was none of hips with migration and/or rotation of an acetabular cup. Radiolucent zone was found in the zone-C of 8 hips. The width of radiolucent zone of all 8 hips was less than 2mm. In these 8 hips, medial protrusio technique was done in 5 hips, and high hip center was found in 3 hips. The radiolucency appeared at postoperatively 2–3 months and disappeared by postoperatively 12 months. Conclusions. All hips showed rigid fixation of a Trabecular Metal Modular Acetabular System in short-term observation. Even in the hips performed Dorr's medial protrusio technique, a Trabecular Metal Modular Acetabular System reached the stable fixation. Radiolucent zone was found transiently in the zone-C of 8 hips (25.8%) and disappeared by postoperatively 12 months. However our series was small and the observation period was short, our results implied that the fixation of a Trabecular Metal Modular Acetabular System was not affected adversely from Dorr's medial protrusio technique

Introduction. Acetabular component loosening with associated bone loss is a challenge in revision hip arthroplasty. Trabecular Metal (TM) by Zimmer Biomet has been shown to have greater implant survivorship for all-cause acetabular revision in small cohort retrospective studies. Our study aims to review outcomes of acetabular TM implants locally. Method. This is a retrospective observational study using data from Auckland City and North Shore Hospitals from 1st of January 2010 to 31st of December 2020. Primary outcome is implant survivorship (re-revision acetabular surgery for any cause) demonstrated using Kaplan-Meier analysis. Secondary outcome is indication for index revision and re-revision surgery. Multivariate analysis used to identify statistically significant factors for re-revision surgery. Results. 225 cases used acetabular TM implants (shells and/or augments) over 10 years. Indications include aseptic loosening (63%), instability (15%) and infection (13%). Of these, 12% (n=28) had further re-revision for infection (54%) and instability (21%). Median time to re-revision was 156 days (range 11 – 2022). No cases of re-revision were due to failure of bony ingrowth or acetabular component loosening. Ethnicity, smoking status, and age were not risk factors for re-revision procedures. Additionally, previous prosthetic joint infection, ethnicity, sex and age were not significant risk factors for re-revision due to infection. Implant survivorship was 80% at 1 year, 71% at 5 years and 64% at 10 years. Discussion. Main indications for re-revision were infection and instability. Demographic factors and co-morbidities did not correlate with increased re-revision risk. Survivorship is poorer compared to cumulative survivorship reported by the New Zealand Joint Registry (NZJR). Explanations are multifactorial and possibly contributed by underestimation of true revision rates by registry data. Conclusions. We need to identify alternate causes for poorer survivorship and review the role of TM implants in acetabular revision within our specified population

Although total hip arthroplasty is highly successful for treatment of osteoarthrosis of hip joint, it is skill demanding surgery to perform and even more challenging in case of revision with bone defects. There are many options available for reconstruction of acetabular bony defects. Here, we evaluate the outcome of acetabular bony defect reconstructed with trabecular metal augments in short term. We performed, 22 revision total hip arthroplasties and 6 primary total hip arthroplasties (total 28 in 28 patients) using trabecular metal augments to reconstruct acetabular defect between 2011 to 2015. Out of these 28 patients, 18 were males and 10 were females. Mean age of these patients was 61.2 years (range: 46 years to 79 years). Pre-operative templating was done for all cases and need for trabecular metal augments was anticipated in all cases. All cases were classified according to Paprosky classification for acetabular bone defects. Out of 28 patients, 3 had type 2B, 1 had type 2C, 18 had type 3A and 6 had type 3B acetabular defects. Post operatively, all patients were followed at regular interval for their clinical and radiological outcome. An average follow up was 20.1 months (range: 6 months to 42.5 months). We assessed clinical outcome in the form of Herris hip score (HHS) and radiological outcomes in form of osteolysis in acetabular zones and osseointegration, according to the criteria of Moore. The average Harris hip score (HHS) was improved from 58.0 preoperatively to 87.2 postoperatively. The average degree of cup abduction at the final follow up was 44.29. The centre of rotation of the hip joint was corrected from average 38.90mm (range: 22.15mm to 66.35mm) above the inter-teardrop line preoperatively to average 23.85mm (range: 11.82mm to 37.69mm) above the inter-teardrop line postoperatively. Out of 28 patients, 18 patients had three or more signs of osseointegration, according to the criteria of Moore, at the time of final follow up. Rest of patients, had one or two signs of osseointegration (5 patients had one sign and 5 patients had two signs). We had no patient with migration or loosening of acetabular components. No patient has osteolysis of acetabulum in any zone. Trabecular metal augments provide good initial stability to acetabular cup as well as helpful to bring down the centre of rotation of the hip joint within limit of 35mm above the inter-teardrop line. They also facilitate osseointegration. Our study showed that the results of the trabecular metal augments in reconstruction of acetabular bony defects were successful even in short term. However, long term study is required for better evaluation

Introduction: It is desirable to delay or avoid total joint replacement in young patients who have osteonecrosis of femoral head. There are some head preserving surgical procedures that attempt this including osteotomy, core decompression, and bone grafting. The vascularized fibular graft has been reported to be a reliable procedure, but unfortunately it has donor site morbidity and is considered technically demanding. Therefore, materials have been developed to substitute for structural fibular graft. New trabecular metal has been developed to be used for osteonecrosis of femoral head. The purpose of this study was to review the clinical outcomes of trabecular metal as a treatment intervention method for osteonecrosis of the femoral head. Materials and Methods: Seven patients (8 hips) with osteonecrosis of femoral head received core decompression and a trabecular metal implant, beginning in March 2003. The stage of osteonecrosis was I or II according to Ficat and Arlet except for one case (stage III). The procedure consists of a core decompression and insertion of trabecular metal rod (porous tantalum, Zimmer Inc./ Implex Incorporation). A Harris Hip Score was obtained pre-operatively, and at three and at three and six months. Radiographic data was collected at the same time of clinical follow-up. Results: All 7 patients are doing well. Radiographic review shows no evidence of further femoral head collapse. Discussion: Even though this is short term follow-up, the authors propose that the use of trabecular metal in osteonecrosis patients is simple, safe, and effective for the salvage of the hip

Compromised patellar bone stock poses significant the chnical problems in primary and revision knee arthroplasty. In these situations, traditional approaches have included: non resurfacing, patellectomy, patellar bone grafting, ‘Gull-Wing’ osteotomy. A new material (Trabecular Metal) fabricated using a tantalum metal and vapor deposition techhnique that create a metallic strut configuration with 80%porosity, and physical and mechanical properties similar to bone has been introduced. The authors studied the short-term results following patellar resurfacing using trabecular metal patella in primary and revision total knee arhroplasty (TKA). Nine patients undergoing primary (2 cases) or revision (7 cases) TKA with the use of a trabecular metal patella were evaluated at a mean of 16 months follow-up. All patients had marked patellar bone deficiency precluding resurfacing with a standard cemented patellar button. The all polyethylene patela was cemented into the trabecular metal base and the remaining patella bone stock; additional fixation was provided by # 2 non absorbable sutures through the peripheral holes on the metal shell. Revision TKA may be complicated by severe patellar bone loss that preclude implantantion of a standard cemented patellar component. Several options including patellectomy, non resurfacing and osteotomy or grafting of remaining bony shell have been proposed. It is rare in primary knee arthroplasty that the patella has been so eroded that resurfacing is not feasible. Trabecular metall patella may be indicate in the complex revision or even primary knee arthroplasty in which all that remains of the patella is a thin shell of anterior cortical. The short-term results of patellar resurfacing with trabecular metal have demonstrated favorable results

Background. Synthetic interbody spinal fusion devices are used to restore and maintain disc height and ensure proper vertebral alignment. These devices are often filled with autograft bone to facilitate bone bridging through the device while providing mechanical stability. Nonporous polyetheretherketone (PEEK) devices are widely used clinically for such procedures. 1. Trabecular Metal devices are an alternative, fabricated from porous tantalum. It was hypothesized that the porous Trabecular Metal device would better maintain autograft viability through the center of the device, the ‘graft hole’ (GH). Methods. Twenty-five goats underwent anterior cervical discectomy and fusion using a Trabecular Metal or PEEK device for 6, 12 or 26 weeks. The GH of each device was filled with autograft bone morsels harvested from the animal at implantation. Fluorochrome labeling oxytetracycline was administered to the animals and used to determine bone viability in the device regions. Following necropsy, the vertebral segments were embedded in poly(methyl methacrylate) sectioned and analyzed using fluorescence and backscatter electron (BSE) imaging. The percent of bone tissue present within the GH was measured as a volume percent using BSE images (Fig. 1). Results. Bone percent analysis demonstrated that there was no significant difference (p<0.05) in volume of bone tissue within the GH of the two devices at 6 and 26 weeks (Fig. 2). At 12 weeks the animals implanted with the Trabecular Metal device had significantly greater volumes of bone within the GH region. Viable bone was observed in the host bone region and periprosthetic to the implant of all PEEK (n=12) and Trabecular Metal (n=12) animals within the study, determined by the presence of fluorescent labels (Fig. 3). Viable bone was also observed in the GH region of all animals with a Trabecular Metal device. However, only 5 of 12 PEEK animals showed bone viability within the GH (2 at 12 weeks and 3 at 26 weeks). A Fisher's exact comparison of the number of animals with viable bone in the GH showed a significant difference between the two devices, p<0.05. Conclusion. Autograft viability was better maintained within the GH for the porous Trabecular Metal device compared to the PEEK device. Although the amount of bone tissue within the GH of the PEEK devices was determined to have no significant difference compared to the Trabecular Metal devices at 6 and 26 weeks, the GH bone tissue was not viable in a number of the PEEK animals at each time point. The interconnected network and high volume porosity of the Trabecular Metal device may have allowed for fluid exchange, angiogenesis and increased blood supply to the autograft morsels. The viability of the autograft morsels also played an important role in the success of bone bridging through the GH between the vertebral endplates. In this animal model it was demonstrated that the autograft bone placed within the PEEK spinal fusion device did not always remain viable after implantation, but sometimes only filled the GH and did not necessarily facilitate fusion between the vertebrae as intended

Aims. Reverse total shoulder arthroplasty (RTSA) using trabecular metal (TM)-backed glenoid implants has been introduced with the aim to increase implant survival. Only short-term reports on the outcomes of TM-RTSA have been published to date. We aim to present the seven-year survival of TM-backed glenoid implants along with minimum five-year clinical and radiological outcomes. Methods. All consecutive elective RTSAs performed at a single centre between November 2008 and October 2014 were reviewed. Patients who had primary TM-RTSA for rotator cuff arthropathy and osteoarthritis with deficient cuff were included. A total of 190 shoulders in 168 patients (41 male, 127 female) were identified for inclusion at a mean of 7.27 years (SD 1.4) from surgery. The primary outcome was survival of the implant with all-cause revision and aseptic glenoid loosening as endpoints. Secondary outcomes were clinical, radiological, and patient-related outcomes with a five-year minimum follow-up. Results. The implant was revised in ten shoulders (5.2%) with a median time to revision of 21.2 months (interquartile range (IQR) 9.9 to 41.8). The Kaplan-Meier survivorship estimate at seven years was 95.9% (95% confidence interval (CI) 91.7 to 98; 35 RTSAs at risk) for aseptic mechanical failure of the glenoid and 94.8% (95% CI 77.5 to 96.3; 35 RTSAs at risk) for all-cause revision. Minimum five-year clinical and radiological outcomes were available for 103 and 98 RTSAs respectively with a median follow-up time of six years (IQR 5.2 to 7.0). Median postoperative Oxford Shoulder Score was 38 (IQR 31 to 45); median Constant and Murley score was 60 (IQR 47.5 to 70); median forward flexion 115° (IQR 100° to 125°); median abduction 95° (IQR 80° to 120°); and external rotation 25° (IQR 15° to 40°) Scapular notching was seen in 62 RTSAs (63.2%). Conclusion. We present the largest and longest-term series of TM-backed glenoid implants demonstrating 94.8% all-cause survivorship at seven years. Specifically pertaining to glenoid loosening, survival of the implant increased to 95.9%. In addition, we report satisfactory minimum five-year clinical and radiological outcomes. Cite this article: Bone Joint J 2021;103-B(8):1333–1338

The introduction of porous tantalum metal (Trabecular Metal; Zimmer, Warsaw, IN) for acetabular component fixation in total hip arthroplasty has shown optimum fixation qualities and “gap filling” effect. Recently, trabecular metal was introduced in tibial component for total knee prosthesis, however its effect on the bone mineral density (BMD) was not reported. The purpose of this study was to compare the BMD of proximal part of the tibia between trabecular metal and another cemented tibial component. 31 knees receiving trabecular metal tibial component and 33 knees receiving cemented tibial component (PFC Sigma RP, Depuy, Warsaw, IN) had dual energy x-ray absorptiometry (DEXA) scans at preoperatively and 3 weeks, 3, 6, 12, 18, 24 months post-operatively. To assess peri-prosthetic BMD, three regions of interest (ROI) were measured for each case. They were medial aspect (ROI 1), center aspect (ROI 2) and lateral aspect (ROI 3) of tibia. Average follow up period was 1.8 (range: 1.5 to 2) years. In both groups, BMD in tibia decrease postoperatively. Comparing postoperative decrease of BMD in lateral aspect of tibia (ROI 3) between both groups, it was significantly less in trabecular metal component (−0.09 g/cm2 +/−0.27) than cemented tibial component (−0.31 g/cm2 +/− 0.21) (p=0.0007). We conclude that trabecular metal tibial component showed a favorable effect on BMD of proximal part of the tibia after total knee arthroplsaty

Introduction: Porous Tantalum has been used in a variety of clinical settings since 1997. The use of trabecular metal backed prostheses and augments in the revision hip scenario is attractive due to the higher propensity of bony ingrowth than traditional porous coatings, and also the high coefficient of friction with bone leads to excellent press fit. We describe the early results of twenty trabecular metal backed acetabular components in the revision setting. Methods: From 2004, 20 patients received trabecular metal backed acetabular components as a revision hip procedure. The average age of the patients was 69 (42–84) yrs at the time of surgery. 4 patients had trabecular metal shells with cemented liners, 16 patients had modular trabecular metal implants. Structural allograft was used in 2 cases, trabcular metal augment in 1. Revision was for aseptic loosening in 17 cases, infection in 3. Acetabular defects were graded according to Paprosky as 2A(10), 2B(1), 2C(1), 3A(6) and 3B(2). Fixation was augmented in all cups with at least one screw. Patients were evaluated with standard x-rays for osteolysis and migration, Harris hip score, SF 36 and Oxford hip score. Results: Average follow up was 12 months (24–5). 100% follow up was achieved. There were no complications directly related to the acetabular surgery. There were no revisions. There are no progressive radiolucencies or detectable migration in any of the cups. There were no dislocations. Conclusion: These early results suggest that trabecular metal backed acetabular components may be confidently used in the setting of hip revision surgery and show promise for the more severe defects for which a reliably reproducible solution has yet to be proven

Purpose. To evaluate the five year Radiostereometric Analysis (RSA) results of the NexGen LPS Trabecular Metal Tibial Monoblock component (TM) and the NexGen Option Stemmed cemented component (Cemented), (Zimmer, Warsaw IN). Method. 70 patients with osteoarthritis were included in a randomized series to receive either the TM implant or the cemented NG component. Surgery was performed by high volume arthoplasty specialists using standardized procedure. RSA exams were obtained postoperatively, at six months, one year, two years and five years. RSA outcomes were translations, rotations and maximum total point motion (MTPM) of the components. MTPM values were used to classify implants as ‘at risk’ or ‘stable’. Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores were gathered at all follow-ups. An analysis of variance was used to test for differences in age, body mass index (BMI), and subjective measures between implant groups. The Kruskal-Wallis test was used to investigate differences in maximum total point motion between implant groups. An analysis of variance was used to test for differences in translations and rotations between groups. Fishers exact test was used to investigate differences in proportions of implants found to be at risk between groups. Results. At the five year follow-up, 43 patients were able to be reached and were willing to participate in the follow-up exam. There were 25 in the trabecular metal group and 18 in the cemented group. There were no differences in subjective measures (WOMAC) between implant groups at any follow-up. At the five year follow-up there was no difference in MTPM between the cemented and trabecular metal groups (p=0.94) Compared to the cemented components, the trabecular metal tibial components had significantly higher subsidence than the cemented components (p=0.001). There were no other significant differences. The proportion of at risk components at five years was 2 of 16 (0.11, 95% CI, 0.03–0.33) in the cemented group and was 0 of 25 (0.0, 95% CI, 0.0–0.13) in the trabecular metal group (p=0.17). Conclusion. In the two year report on this cohort of patients, we indicated our uncertainty concerning the long term stability of the Trabecular Metal tibial implant due to the high initial migration seen in some cases. In this report we have seen stability of this implant out to five years and migrations in this period below the level of detection of our system in all cases. Given these results it is with increased confidence that we can state that this implant appears to achieve solid fixation despite high initial levels of migration

The trabecular metal Monoblock TKR is comprised of a porous tantalum base plate with the polyethylene liner embedded directly in the porous metal. An alternative design, the trabecular metal Modular TKR, allows polyethylene liner insertion into the locking base plate after base plate implantation, but removes the low modulus of elasticity that was inherent in the Monoblock design. The purpose of this study was to compare the fixation of the Monoblock and Modular trabeucular metal base plates in a randomised controlled trial. Fifty subjects (30 female) were randomly assigned to receive the uncemented trabecular metal Monoblock or uncemented trabecular metal Modular knee replacement. A standard procedure of tantalum marker insertion in the proximal tibial and polyethylene liner was followed with uniplanar radiostereometric analysis (RSA) examinations immediately post-operatively and at 6 week, 3 month, 6 month, and 12 month follow-ups. The study was approved by the Research Ethics Board and all subjects signed an Informed Consent Form. Twenty-one subjects received Monoblock components and 20 received Modular components. An intra-operative decision to use cemented implants occurred in 5 cases and 4 subjects did not proceed to surgery after enrollment. The clinical precision of implant migration measured as maximum total point motion (MTPM) was 0.13 mm (upper limit of 95% confidence interval of double exams). Implant migration at 12 months was 0.88 ± 0.64 mm (mean and standard deviation; range 0.21 – 2.84 mm) for the Monoblock group and 1.60 ± 1.51 mm (mean and standard deviation; range 0.27 – 6.23 mm) for the Modular group. Group differences in 12 month migration approached clinical significance (p = 0.052, Mann Whitney U-test). High early implant migration is associated with an increased risk for late aseptic loosening. Although not statistically significant, the mean migration for the Modular component group was nearly twice that of the Monoblock, which places it at the 1.6 mm threshold for “unacceptable” early migration (Pijls et al 2012). This finding is concerning in light of the recent recall of a similar trabecular metal modular knee replacement and adds validity to the use of RSA in the introduction of new or modified implant designs. Reference: Pijls, B.G., et al., Early migration of tibial components is associated with late revision: a systematic review and meta-analysis of 21,000 knee arthroplasties. Acta Orthop, 2012. 83(6): p. 614–24

Management of severe bone loss in total knee arthroplasty presents a formidable challenge. This situation may arise in neglected primary knee arthroplasty with large deformities and attritional bone loss, in revision situations where osteolysis and loosening have caused large areas of bone loss and in tumor situations. Another area of large bone loss is frequently seen in periprosthetic fractures. Trabecular metal (TM) with its dodecahedron configuration and modulus of elasticity between cortical and cancellous bone offers an excellent bail out option in the management of these very difficult situations. Severe bone loss in the distal femur and proximal tibia lend themselves to receiving the TM cones. The host bone surfaces need to be prepared to receive these cones using a high speed burr. The cones acts as a filler with an interference fit through which the stemmed implant can be introduced and cemented. All areas of bone void is filled with morselised cancellous bone fragments. We present our experience of 64 TM cones (28 femoral, 36 tibial cones) over a 10-year period and our results and outcomes for the same. We have had to revise only one patient for recurrence of the tumor for which the cone was implanted in the first place. We also describe our technique of using two stacked cones for massive distal femoral bone loss and its outcomes. We found excellent osteointegration and new host bone formation around the TM construct. The purported role of possible resistance to infection in situations using the TM cones is also discussed. In summary we believe that the use of the TM cones offers an excellent alternative to massive allografts, custom and/or tumor implants in the management of massive bone loss situations

Introduction: Trabecular Metal (Tantalum) has been successfully used in Neurosurgery for many years. Acetabular components have only been available in the UK since 2004. The metal’s properties of porosity and a high friction coefficient are attractive, particularly in complex primary and revision hip arthroplasty when surgical challenges include abnormal, deficient or limited bone. Methods: Two year results of 110 consecutive acetabular reconstructions are presented. The age range was between 27 and 95 years with a predominance of females. The indication in 75 primary hip replacements included, Destructive Osteoarthritis, Dysplasia, Rheumatoid Arthritis, Paget’s and AVN. 35 revisions were performed either two-component or single acetabular exchanges. Clinical results have been obtained using the Merle d’Aubigne score and bone deficiencies were classified according to the AAOS system. Results: There have been no failures and radiologically, serial X-rays demonstrate osseo-integration at an early stage. We have had no cases of deep infection but there have been 3 femoral peri-prosthetic fractures, (1 late) and 2 dislocations. All patients have been allowed early weight bearing and those patients with over 12 months follow up have an improved Merle d’Aubigne score. Discussion: The biomechanical properties of Trabecular metal and a modular design permit a press fit technique supplemented by dome screws combined with the possibility of using varying sizes of liner to minimise dislocation or to retain well fixed femoral stems in revision surgery. The ease of use of the implant has now led to us largely abandoning other reconstructive techniques such as impaction allo-grafting or cages in revision or complex primary hip surgery. We consider Trabecular metal to be a major advance in acetabular reconstruction on the basis of our initial experience

The best treatment method of large acetabular bone defects at revision THR remains controversial. Some of the factors that need consideration are the amount of residual pelvic bone removed during revision; the contact area between the residual pelvic bone and the new implant; and the influence of the new acetabular construct on the centre of rotation of the hip. The purpose of this study was to compare these variables in two of the most used surgical techniques used to reconstruct severe acetabular defects: the trabecular metal acetabular revision system (TMARS) and a custom triflanged acetabular component (CTAC). Pre- and post-operative CT-scans were acquired from 11 patients who underwent revision THR with a TMARS construct for a Paprosky IIIB defect, 10 with pelvic discontinuity, at Royal Adelaide Hospital. The CT scans were used to generate computer models to virtually compare the TMARS and CTAC constructs using a semi-automated method. The TMARS construct model was calculated using postoperative CT scans while the CTAC constructs using the preoperative CT scans. The bone contact, centre of rotation, inclination, anteversion and reamed bone differences were calculated for both models. There was a significant difference in the mean amount of bone reamed for the TMARS reconstructions (15,997 mm. 3. ) compared to the CTAC reconstructions (2292 mm. 3. , p>0.01). There was no significant difference between overall implant bone contact (TMARS 5760mm. 2. vs CTAC 5447mm. 2. , p=0.63). However, there was a significant difference for both cancellous (TMARS 4966mm. 2. vs CTAC 2887mm. 2. , p=0.008) and cortical bone contact (TMARS 795mm. 2. vs CTAC 2560mm. 2. , p=0.001). There was no difference in inclination and anteversion achieved. TMARS constructs resulted on average in a centre of rotations 7.4mm more lateral and 4.0mm more posterior. Modelling of two different reconstructions of Paprosky IIIB defects demonstrated potential important differences between all variables investigated

Introduction: Autologous bone graft is currently considered the gold standard for anterior cervical discectomy and fusion (ACDF). However, the harvesting of bone graft from the ilac crest is frequently associated with significant patient morbidity. We report on the safety and efficacy of trabecular metal blocks for achieving a stable interbody fusion for ACDF when compared to iliac crest bone graft for a small group of patients. Methods: This is a prospective trial of patients who underwent consecutive ACDFs between September 2004 and September 2007. Patients received one of two materials for their fusion, either trabecular metal blocks or autologous iliac crest bone graft. Each operation was performed by the same spinal surgeon (LT), and all patients had fixation with an anterior titanium plate to enhance interbody arthrodesis. Clinical outcome was assessed with a neck disability score (Vernon and Mior 1991) that was mailed to all participants; bone graft patients were also asked to complete a bone graft morbidity questionnaire (Silber et al. 2003). Radiological followup was assessed with computed tomography and flexion-extension radiographs. A minimum followup time of 3 months was required for inclusion into the study, and unpaired t-tests were used to evaluate statistical differences between relevant sets of data. Results: A total of 31 patients were included into the study, with 15 in the trabecular metal group (TM) and 16 in the iliac crest bone graft group (ICBG). The TM group included 10 males (67%) with a median age of 42 years (range 18–72). Median neck disability score was 18% (2–38) and stable bony ingrowth was observed in all patients (100%) on postoperative scans. Median followup time was 8 months (3–16) for TM patients and 20.3 months (7–36 months) for the ICBG group. In comparison, the ICBG group included 8 males (50%) with a median age of 53.3 years (43–70). Median neck disability score was worse at 30% (4–50), with a significant difference of 12% observed after t-test analysis (p value < 0.02). In addition, there was significant morbidity associated with the harvesting of autologous bone graft, with more than 50% of patients experiencing acute and/or chronic symptoms. Two radiological pseudoarthroses (8%) were observed postoperatively, of which one was manifested clinically. Discussion: These results confirm that, for our population group, trabecular metal implants are both safe and effective for use in ACDF when compared to the gold standard of autologous bone graft. Furthermore, trabecular metal implants avoid the morbidity associated with the harvesting of iliac crest bone graft. We believe the results so far are encouraging for our small group of patients but a larger, randomised control trial is needed to provide definitive results

To evaluate the effectiveness of core decompression using the tantalum trabecular metal system for treatment of an early stage osteonecrosis of femoral head in minimum 1 year to maximum 5 years follow-up. From January 2003 to August 2007, 36 patients in 46 cases underwent core decompression using the tantalum trabecular metal system. The ARCO classification system was used. Retrospective analysis was done. The conversion to total hip arthroplasty due to aggravating hip pain was defined as a clinical failure. With the higher stage of ARCO classification and more lateral location of lesion, the conversions to total hip arthroplasty would be increased. The better outcome was noted with lower stage of ARCO classification and more medial location of the lesion. The higher stage of ARCO classification and more lateral position of lesion, the failure rate of the tantalum trabecular metal system increases. The most important thing is to detect early stage of osteonecrosis of femoral head. The tantalum trabecular metal system is considered as a useful treatment of osteonecrosis of femoral head with lower stage of ARCO classification and medial location of lesion

Introduction: The ideal acetabular component has low wear, permanent fixation and physiological bone loading. Recently trabecular metal has been promoted as reproducing the modulus of trabecular bone with a cementless fixation. The aim of this trial was to see if a monobloc trabecular backed polyethylene acetabular component loaded the pelvis physiologically as a cemented polyethylene component. Method: Between 2004 and 2006 54 patients were ran-domised to a cemented polyethylene acetabular component versus a monobloc trabecular backed polyethylene acetabular component. The primary outcome measurement was bone density in peri-prosthetic acetabular regions of interest measured preoperatively and post operatively at 6 weeks and 1 year. Secondary outcomes measured were radiographic and functional outcomes (HHS and Oxford score). Results: Radiographically 8 patients in the trabecular group had a significant gap in zone II which resolved in 6 by 1 year. The cemented group had 3 patients with a radiolucent line (zone 1) at 1 year. HHS and OXFORD scores improved with no significant difference between the groups. Both groups had significant loss of bone density in the ilium and ischium. The trabecular group produced a significant increase in bone density in the superolateral region. The cemented group produced increased bone density in the superomedial region. Discussions and Conclusions: There is a significant reduction in BMD for both groups in the upper pelvis and ischium in keeping with finite element modelling predictions. The press-fit group relative to the cemented group resulted in decreased BMD in the superomedial peri-prosthetic region. The trabecular monobloc cup therefore behaves more like a rigid cementless shell despite the properties of trabecular metal

Introduction We report the early results of a series of 80 primary total knee replacements (TKRs) using a trabecular metal tibial component (TMT). Methods Significant tibial bone loss and scarcity of kit were the only reasons for patients not receiving a TMT. Age, sex, diagnosis and body mass index (BMI) were recorded. Patients were scored pre-operatively using the Oxford Knee and SF-12 scores. These were repeated at subsequent clinical follow up where standard X-rays were also taken. Range of movement was estimated using a goniometer and stability assessed clinically. This regimen was identical to that in place for the standard knee previously used by the senior author with a cemented tibial component and this group is used in comparison as possible. Results To date there are 80 TMT knees in the series with 36 standard cemented TKRs in comparison. The mean age of the whole series is 70 years (20–90) with no difference between the groups. Sixty five per cent of the series were female. All bar three patients had osteoarthritis. The mean BMI was 30.3 (20.9–46.2). The mean pre-op Oxford score was 45.8 in the TMT group and 44.5 in the cemented group. At a mean follow up of 13.3 (9–17) months in the TMT group and 18.7 (9–19) months in the cemented group this fell to 22.5 and 20.5 respectively. The physical component of the SF-12 score improved from 27.3 to 40.7 in the TMT group and from 27.5 to 45.5 in the cemented group. There was no statistical difference between the groups using either score. The mean amount of flexion pre-operatively was 106 (65–135) degrees for the series. This was maintained postoperatively at 105 degrees (70–125) with no difference between the groups. There was one deep infection in the cemented group that underwent revision and one non-fatal pulmonary embolus in the cemented group. There were no worrying radiological signs in either group. Conclusion Trabecular metal is made from elemental tantalum. The TMT is an uncemented component with a truly porous structure for bone ingrowth and a modulus of elasticity equivalent to bone that allows physiological transfer of stresses. The early clinical and radiological results are equal to a cemented prosthesis. Further follow up is required to see whether this is maintained over time

We have evaluated the function of a trabecular metal augmentation patella to restore knee kinetics and kinematics after revision total knee arthroplasty. An “Oxford type” rig was used with fresh frozen cadaveric knees, for an active model that maximally retained the soft tissue envelope. Investigating the force through the extensor mechanism, we found a statistically significant difference between the TKA before and after patelloplasty, which was abolished by the insertion of the augmentation patella. Investigation patella tracking, we found a statistically significant difference between the TKA before and after patelloplasty, that was rectified by the insertion of the augmentation patella. The purpose of this study is to evaluate the kinetic and kinematic function of a new trabecular metal augmentation patella. Investigating the force through the extensor mechanism, we found a statistically significant difference between the TKA before and after patelloplasty, which was abolished by the insertion of the augmentation patella. Investigation patella tracking, we found a statistically significant difference between the TKA before and after patelloplasty, that was rectified by the insertion of the augmentation patella. This study demonstrates that the augmentation patella restorers the abnormal tracking and higher extensor mechanism forces seen after patelloplasty in revision TKA to those normal after a TKA. The mean, maximum extensor mechanism force in extension for the TKA group as compared to the patelloplasty group (p=0.0000032), reduced to near normal with the augmentation patella (p=0.198). The mean, maximum patella maltracking in extension for the TKA group as compared to the patelloplasty group (p=0.025), reduced to near normal with the augmentation patella (p=0.301). Eight frozen human cadaveric knees (mean age sixty-eight years) were prepared for an “Oxford type” knee rig. Alignment ands offset were addressed and the soft tissue envelope kept as intact as possible. A load cell was introduced into the extensor mechanism. Femoral, patella and tibial motion were assessed using the Optotrak system. Patella bone loss at revision TKA remains an unsolved problem, with the patella often too thin to accept a new prosthesis. Leaving the patella shell to articulate against the femoral component can lead to disappointing results. Funding - Zimmer

We have evaluated the function of a trabecular metal augmentation patella to restore knee kinetics and kinematics after revision total knee arthroplasty. An “Oxford type” rig was used with fresh frozen cadaveric knees, for an active model that maximally retained the soft tissue envelope. Investigating the force through the extensor mechanism, we found a statistically significant difference between the TKA before and after patelloplasty, which was abolished by the insertion of the augmentation patella. Investigation patella tracking, we found a statistically significant difference between the TKA before and after patelloplasty, that was rectified by the insertion of the augmentation patella. The purpose of this study is to evaluate the kinetic and kinematic function of a new trabecular metal augmentation patella. Investigating the force through the extensor mechanism, we found a statistically significant difference between the TKA before and after patelloplasty, which was abolished by the insertion of the augmentation patella. Investigation patella tracking, we found a statistically significant difference between the TKA before and after patelloplasty, that was rectified by the insertion of the augmentation patella. This study demonstrates that the augmentation patella restorers the abnormal tracking and higher extensor mechanism forces seen after patelloplasty in revision TKA to those normal after a TKA. The mean, maximum extensor mechanism force in extension for the TKA group as compared to the patelloplasty group (p=0.0000032), reduced to near normal with the augmentation patella (p=0.198). The mean, maximum patella maltracking in extension for the TKA group as compared to the patelloplasty group (p=0.025), reduced to near normal with the augmentation patella (p=0.301). Eight frozen human cadaveric knees (mean age sixty-eight years) were prepared for an “Oxford type” knee rig. Alignment ands offset were addressed and the soft tissue envelope kept as intact as possible. A load cell was introduced into the extensor mechanism. Femoral, patella and tibial motion were assessed using the Optotrak system. Patella bone loss at revision TKA remains an unsolved problem, with the patella often too thin to accept a new prosthesis. Leaving the patella shell to articulate against the femoral component can lead to disappointing results. Funding - Zimmer

We compared internal fixation augmented with a trabecular metal implant to internal fixation augmented with morcellized bone grafting for depressed lateral tibial plateau fractures. Six cadaveric tibia pairs were prepared and tested on a MTS machine for both cyclic loading and static load to failure. Results showed greater resistance in cyclic loading and load to failure in the trabecular metal group. We found half the loss of reduction of the tibial articular surface compared after cyclic loading over 10 000 cycles. These surprising results show the biomechanical superiority of our trabecular metal construct over the current standard of care. Restoration and maintenance of the plateau surface are the key points in the treatment of tibial plateau fractures. Any deformity of the articular surface jeopardises the future of the knee by causing osteoarthritis and axis deviation. The purpose of this study is to develop a more solid way to fix the Shatzker III fracture and to test a trabecular metal implant in the trauma setting for the first time. Six matched pairs of fresh frozen human cadaveric tibias were fractured and randomly assigned to be treated with either the standard of care (two 4,5mm cortical raft screws augmented with morcellized bone graft) or the new method (the same screws supporting a 2 cm diameter trabecular metal disc placed under the comminuted articular surface). The specimens were tested in cyclic loading and put at load to failure. The trabecular metal construct showed 40% less caudad displacement of the articular surface (1,43 mm vs 0,81 mm) in cyclic loading (p< 0.05). Its mechanical failure occurred at a mean of 3275 N compared to 2650 N for the standard of care construct (p< 0,05). The current study shows the biomechanical superiority of our trabecular metal construct compared to the current standard of treatment with regards to both its resistance to caudad displacement of the articular surface in cyclic loading and its strength at load to failure. Trabecular metal is a good metaphyseal void filler in the studied fracture

Trabecular metal (TM) augments are designed to support an uncemented socket in revision surgery when adequate rim fit is not possible. We have used TM augments in an alternative arrangement, to contain segmental defects to facilitate impaction bone grafting (IBG) and cementation of a cemented socket. However, there is a paucity of literature supporting the use of this technique. We present one of the largest studies to date, reporting early outcomes of patients from a tertiary centre. A single-centre retrospective analytical study of prospectively collected data was performed on patients who had undergone complex acetabular reconstruction using TM augments, IBG and a cemented cup. All patients operated between 2015 and 2019 were included. We identified 105 patients with a mean age of 74yrs. The mean follow-up was 2.3 years(1–5.5yrs). Our primary outcome measure was all-cause revision of the construct. The secondary outcome measures were, Oxford hip score (OHS), radiographic evidence of cup migration/loosening and post-op complications. Eighty-four out of 105 patients belonged to Paprosky grade IIb, IIc or IIIa. Kaplan-Meier survivorship for all-cause revision was 96.36% (CI, 90.58–100.00) at 2 years with 3 failures. Two were due to early infection which required two-stage re-revision. The third was due to post-operative acetabular fracture which was then re-revised with TM augment, bone graft and large uncemented cup. Pre-op and post-op matched OHS scores were available for 60 hips(57%) with a mean improvement of 13 points. Radiographic analysis showed graft incorporation in all cases with no evidence of cup loosening. The mean vertical cup migration was 0.5mm (Range −5 to 7mm). No other complications were recorded. This study shows that reconstruction of large acetabular defects during revision THA using a combination of TM augments to contain the acetabulum along with IBG to preserve the bone stock and a cemented socket is a reliable and safe technique with low revision rates and satisfactory clinical and radiographic results. Long term studies are needed to assess the possibility of preservation and regeneration of bone stock

Introduction: Avascular Necrosis (AVN) of the femoral head is a complex disease that often leads to disabling hip pain and degenerative arthritis. Core decompression is currently the most common procedure used to treat the early stages of AVN but used alone may not provide adequate structural support. Trabecular metal may be a promising development by providing the support needed after a core decompression while minimizing the surgical complications of bone grafts. The important stiffness is similar to a fibular graft and the implant enables vascular healing via its porosity. This is a small series of patients who underwent this procedure which is minimally invasive. All patients had a non-traumatic aetiology for the AVN and were referred from a Rheumatology clinic closely linked to the orthopaedic clinic. Methodology: This is a retrospective review of consecutive patients who underwent core decompression and insertion of trabecular metal (tantalum) screw for AVN of the femoral head. Preoperatively the severity of the AVN was assessed with the help of a radiologist using a modified Ficat classification (Steinberg 1986) with magnetic resonance imaging. Postoperatively the progression was assessed with x-rays. Results: A total of nine trabecular screws were inserted into five patients with four receiving bilateral operations. Medium age was forty-five years (range 32–57) and 60% males (n=3). Steroids were thought to be the predisposing factor for AVN in all cases. Preoperative MRI studies showed Grade II disease in four hips (44.4%) Grade III in four hips (44.4%) and Grade IV disease in one hip (11.2%) Median follow up time was 14.4 months range (3–27 months). The hip with Grade IV disease went onto develop destruction of the joint and required a total hip replacement fifteen months later. This was a straightforward procedure with easy removal of the implant. The remaining hips have not required revision to date. There have been no implant failures, migration or loosening. This procedure may prove to be a clinically viable implant option for AVN and the study is ongoing. A major problem is the difficulty in seeing patients early enough with early stage disease. (stage 0, stage I and II.) There have been no implant failures migration or loosening to date

Purpose:. Acetabular bone loss during revision total hip arthroplasty (THA) poses a challenge for reconstruction as segmental and extensive cavitary defects require structural support to achieve prosthesis stability. Trabecular metal (TM) acetabular augments structurally support hemispherical cups. Positive short-term results have been encouraging, but mid- to long-term results are largely unknown. The purpose of this study was to determine the continued efficacy of TM augments in THA revisions with significant pelvic bone loss. Methods:. Radiographs and medical records of 51 patients who had undergone THA revision with the use of a TM augment were retrospectively reviewed. Acetabular defects were graded according to the Paprosky classification of acetabular deficiencies based on preoperative radiographs and operative findings. Loosening was defined radiographically as a gross change in cup position, change in the abduction angle (>5°), or change in the vertical position of the acetabular component (>8 mm) between initial postoperative and most recent follow-up radiographs (Figure 1). Results:. Eleven patients had incomplete radiographic follow-up and were excluded. The study population included 17 men and 23 women, averaging 68.1 ± 14.1 years of age (range, 37–91), with average radiographic follow-up of 19.0 months (range, 2.4–97.4). Reasons for revision included osteolysis (n = 20, 38.5%), component loosening (n = 18, 15.4%), and periprosthetic fracture (n = 6, 11.5%). All patients underwent revision THA using a TM multi-hole revision acetabular cup and TM acetabular augment(s) to fill bony defects. Morcellized allograft was used in 9 patients. There were 33 Paprosky Type IIIA and seven Paprosky Type IIIB defects. One patient with Paprosky Type IIIB had catastrophic failure of the reconstructive construct three months postoperatively. The remaining 39 acetabular revisions demonstrated signs of bony ingrowth at the latest follow-up. There were no radiolucent lines suggestive of loosening, and no significant differences in abduction angle (p = 0.78), vertical distance between the superolateral edge of the cup and the trans-ischial reference line (p = 0.96), or the vertical distance between the center of the femoral head and trans-ischial reference line (p = 0.75) between the initial postoperative and most recent follow-up radiographs (Figure 2). Discussion and Conclusion:. Achieving fixation and long-term stability in THA revisions with segmental and/or cavitary bone loss is challenging. TM augments provide a modular structural system to achieve bony ingrowth, while avoiding large structural allografts, cages, and custom implants. At latest follow-up, 39 revision hips remained well-fixed with no evidence of loosening. One patient with a significant surgical history of infection, periprosthetic femur fracture, and 2 prior revision surgeries before acetabular reconstruction had an early clinical failure. Trabecular metal augments can be used for reconstruction of acetabular bone loss with good mid-term results. Continued follow-up is warranted for radiographic evaluation of bony integration and implant stability to determine long-term survivorship of these implants

Introduction. Severely comminuted, displaced acetabular fractures with articular impaction in the elderly population present significant treatment challenges. To allow early post-operative rehabilitation and limit the sequelae of immobility, treatment with acute total hip replacement (THA) has been advocated in selected patients. Achieving primary stability of the acetabular cup without early migration is challenging and there is no current consensus on the optimum method of acetabular reconstruction. We present clinical results and radiostereometric analysis of trabecular metal (TM) cup cage construct reconstruction in immediate THA without acetabular fracture fixation. Methods. Between 2011 and 2016, twenty-one acetabular fractures underwent acute THA with a TM cup cage construct. Patient, fracture and surgical demographics were collected. They were followed up for a mean of 24months (range 12–42months). Clinical and patient reported outcome measures were collected at regular post-operative intervals. Radiosterometric analysis (RSA) was used to measure superior migration and sagittal rotation of the acetabular component. Results. Thirteen fractures were classified as anterior column posterior hemi-transverse, two anterior column, two transverse and four associated both column acetabular fractures. There was one case of trochanteric fracture and transient foot drop. Mean Harris Hip Scores at 12months was 79 (range 33–98). The mean proximal migration of the acetabular components at 12months was 0.91mm (range 0.09–5.12 and mean sagittal rotation was 0.52mm (range 0.03–7.35). Conclusion. The TM cup-cage technique requires a single approach and provides immediate cup stability allowing full weight bearing day one post-op. To our knowledge this is the first study to accurately measure cup stability following THA for an acetabular fracture. Our promising early clinical and radiological outcomes suggest this technique may be an alternative to a fix and replace construct for immediate THA for acute acetabular fractures in the elderly

Background. Trabecular metal (TM) cones are designed to fill up major bone defects in total knee arthroplasty. Tibial components can be implanted in combination with a stem, but it is unclear if this is necessary after reconstruction with a TM cone. Implanting a stem may give extra stability, but may also have negative side-effects. Aim of this study was to investigate stability and strain distribution of a tibial plateau reconstruction with a TM cone while the tibal component is implanted with and without a stem, and whether prosthetic stability was influenced by bone mineral density (BMD). Methods. Tibial revision arthroplasties were performed after reconstruction of an AORI 2B bone defect with TM cones. Plateaus were implanted in seven pairs of cadaveric tibiae; of each pair, one was implanted with and the other without stem. All specimens were loaded to one bodyweight alternating between the medial and lateral tibia plateau. Implant-bone micro motions, bone strains, BMD and correlations were measured and/or calculated. Results. Tibial components without a stem showed only more varus tilt (difference in median 0.14 degrees (P<0.05), but this was not considered clinically relevant. Strain distribution did not differ. BMD had only an effect on the anterior/posterior tilt ρ:-0.72 (P<0.01). Conclusions. Tibial components, with or without a stem, which are implanted after reconstruction of major bone defects using TM cones produce very similar biomechanical conditions in terms of stability and strain distribution. Additional stem extension of the tibial component may not be required after reconstruction of major bone defects using TM cones. Level of evidence. IIb. Disclosures. The department of Orthopaedics, University of Groningen, University Medical Center Groningen has received direct funding from the Anna Fonds (Oegstgeest, NL). Zimmer (Warsaw, IN, USA) has provided the instrumentation and tools for this study. The department of Orthopaedics, University of Groningen, University Medical Center Groningen receives research institutional support from InSpine (Schiedam, NL) and Stryker (Kalamazoo, Mich. USA). One of the authors (ALB) will be and has been paid as a consultant by Zimmer (Warsaw, IN, USA) for purposes of education and training in knee arthroplasty

INTRODUCTION. Total knee arthroplasty (TKA) is typically performed using cement to secure the prosthesis to bone. There are complications associated with cementing that include intra-operative hypotension, third-body abrasive wear, and loosening at the cement interfaces. A cementless prosthesis using a novel keeled trabecular metal tibial baseplate was developed to eliminate the need for cementing the tibial component in TKA. METHODS. A retrospective chart review was performed on patients who underwent TKA using cementless tibial and femoral components between August, 2013 and January, 2014. Patients with minimum two-year follow-up including radiographs were included in the analysis. Patient demographics as well as preoperative and postoperative range of motion (ROM) and function were measured using the Knee Society Scoring system (KSS). Post-operative radiographs were assessed for signs of osteolysis, loosening, or subsidence. Paired T-tests were used to identify differences in preoperative and postoperative ROM and KSS. RESULTS. Thirty-three patients underwent 48 TKAs in the study period. Of those, 20 patients (29 knees) completed two-year follow-up. The mean patient age was 69.0 ±8.4 years and mean BMI was 29.9 ±4.3. The average time of follow-up was 24.6 months (range 24–29). Preoperative ROM was on average 4.3–117.3°±6.7 and the preoperative KSS knee scores and functional scores were 43.8 ±8.6 and 49.8 ±12.6, respectively. Postoperatively, there were statistically significant improvements in ROM (0–130.7°±7.3), and postoperative KSS knee (98.4 ±3.2) and functional scores (99.3 ±2.6), at two years, respectively. None of the radiographs demonstrated evidence of osteolysis, loosening, migration, or subsidence. DISCUSSION and CONCLUSION. The two-year results of TKA utilizing a cementless tibial baseplate demonstrate excellent results in terms of knee ROM and function. The radiographic evidence of osteointegration without evidence of loosening, subsidence, or migration of the tibial components is promising. Further follow up is necessary to ensure that these implants will provide a satisfactory long-term alternative to cement fixation

Introduction. Several options exist for the treatment of periprosthetic osteolysis in revision knee surgery. We describe our preliminary short-term experiences using trabecular metal (TM) technology in order to fill bony defects either on the femoral or on the tibial side. Material and Methods. 52 revision knee surgeries in which this TM technology had been used were retrospectively reviewed clinically and radiographically. Indication for revision included 51 cases with aseptic loosening of Total Knee Arthroplasty. In one case of periprostheti infection, a staged revision procedure was performed. Assessment of bone loss included the AORI classification (1989) and was performed pre- and intraoperatively. Clinical evaluation was performed using the HSS score. In 6 cases in addition to usng the TM cones, an impaction grafting technique was performed. Results. Average follow up was 22 months. So far, not loosening of a TM cone neither clinically nor radiographically was observed. In 74% of the cases, either a type FII-TII-FIII or TIII defect was seen. Average number of pre-existing surgeries was 4,6. Pre-operative Range of motion was 0-84 degrees and 0-98 degrees at time of latest follow up. Complications in this series included 2 periprosthetic fractures and 1 periprosthetic infection, later revised to a successful fusion. Upon explantation of the TM cone in this case, stable osteointegration was observed. HSS score increased from 34 to 62 points postoperatively (49-93). Discussion. Treatment of severe periprosthetic osteolysis in our eyes can be managed successfully in the short-term range using TM technology which requires a meticulous surgical technique and proper indication. This material might be successfully combined using homologous bone as an adjunct

Pure tantalum has been proposed in orthopaedic surgery. Its chemical and physical properties have been widely studied in the past. From pure tantalum is obtained a spongy structure (Trabecular Metal Technology: TMT) that shows a full thickness porosity which is 2–3 times higher compared to other surfaces available for bone ingrowth with a three-dimensional porous arrangement in rough trabeculae. Pores (average diameter of 650 mm) are fully interconnected and represent 75–80% of the whole volume. TMT acetabular components have an elliptical shape and have an irregular external surface which both allow an optimal mechanical fit. We retrospectively reviewed 212 cases of monoblock porous tantalum acetabular cup (Hedrocel, Stratec) implanted between 1999 and 2003 in a single centre with a minimum follow-up of 9–10 years; There were 98 men and 114 women, with an average age of 65 years. They all underwent primary or revision total hip arthroplasty or to acetabular component revision alone. In all patients a monoblock porous tantalum acetabular component with polyethylene directly compression molded into cup, with or without peripheral holes for screws, was implanted. In all primary procedures the same femoral stem (Synergy, Smith and Nephew) was implanted. All patients were evaluated with a clinical examination (Harris Hip Score: HHS) and with standard radiographs of the pelvis preoperatively and 1, 3, 6 months and yearly postoperatively. The stability of the acetabular cup was determined by modified Engh's criteria. The HHS score improved from 42 preoperatively to 94 after one year; at 13 years follow-up it was 95. The subjective outcome was widely satisfying, with the majority of patients experimenting good functional recovery and return to daily activities. Osteointegration of the acetabular component was present in all X-rays controls at one year after surgery. All post-operative evidence of residual bone loss (geodes, bone defects in revisions and in displasia) were no more radiographically evident after 1 year postoperatively as the host bone quickly filled these gaps. We did not observe osteolysis nor progressive radiolucent lines at the latest follow-up. None of the cups was revised, except 3 cases, revised for infection. Both clinical and radiographic results are the same or even superior to those of coated implants. Our experience confirms that trabecular metal tantalum cups can avoid the formation of bone-implant interface membrane and consequently can avoid implant loosening. The most important advantages of TMT monoblock cups are: no potential for polyethylene backside wear, prevention of loosening and osteolysis, increased early fixation via friction, improved late biological stability, maximum bone-implant contact. High biocompatibility of porous tantalum and its elastic modulus very close to bone influence positively earlier and wider osteointegration of the implant. Larger series are needed to confirm the positive our preliminary results

Purpose: Bone stress transmission by an implant has been demonstrated to be inversely proportional to its rigidity. Since trabecular metal has a high elasticity modulus, it is hypothesised that it should have a preservative impact on bone mineral density (BMD) loss. No current studies prospectively compare BMD variations using such implants. Method: A randomized study recruiting 65 patients with osteoarthritis of the knee, were assigned to a cemented titanium or a non-cemented trabecular metal tibial base plate. Each patient had a DXA scan of the proximal tibia on the TKA side at two weeks, six months, one and two years follow-up. Analytic methods for DXA scans were standardized (Variation coefficient=0,59–0,84%), and BMD variation compared between groups using the Student t-Test. Results: Versus early post operative evaluation, BMD loss was found in the two groups. Fixed effects on BMD, such as patient’s height (p< 0.001) and tibial implant size (p=0.04) were demonstrated. Patella resurfacing and polyethylene thickness had no effect on BMD. BMD loss was more important under titanium implants (−30.9%) than trabecular metal implants (−6.3%). The most affected area was the metaphysis (p=0.002) compared to the diaphysis (p=0.054). Conclusion: Trabecular metal tibial base plate seems to diminish BMD loss under tibial implant compared to traditional titanium base plate. A long-term study will be necessary to determine the tibial trabecular metal component survival rate

Purpose To evaluate the kinetic and kinematic function of a new trabecular metal augmentation patella. Method Eight frozen human cadaveric knees (mean age 68 years) were prepared for an “Oxford type” knee rig. Alignment ands offset were addressed and the soft tissue envelope kept as intact as possible. A load cell was introduced into the extensor mechanism. Femoral, patella and tibial motion were assessed using the Optotrak system. Summary of Results The mean, maximum extensor mechanism force in extension for the TKA group as compared to the patelloplasty group (p=0.0000032), reduced to near normal with the augmentation patella (p=0.198). The mean, maximum patella maltracking in extension for the TKA group as compared to the patelloplasty group (p=0.025), reduced to near normal with the augmentation patella (p=0.301). Conclusion Investigating the force through the extensor mechanism, we found a statistically significant difference between the TKA before and after patelloplasty, which was abolished by the insertion of the augmentation patella. Investigation patella tracking, we found a statistically significant difference between the TKA before and after patelloplasty, that was rectified by the insertion of the augmentation patella

The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky 3A, 3B defects and defects associated with pelvic discontinuity. A retrospective study was conducted of the cases performed at four centers between August 2007 and January 2015. Patients treated with TM augments for Paprosky 3A, 3B or chronic pelvic discontinuity were included in the study. All surgeries were performed through a posterior approach. A total of 57 patients (Male 34 (69%), Female 23(31%)), mean age 54 years (range, 28–94 years), with minimum follow up of one-year were included and evaluated using intention to treat analysis. There were 44 (77%) patients with a 3A defect, 11(19%) patients with a 3B defect (6 had an associated pelvic discontinuity), and 2 (3.5%) with a 2C defect and associated pelvic discontinuity. The mean follow-up was 37 months (range, 12–96 months). One (2%) patient died after 8 years of unrelated causes. Three (5.5%) patients had acetabular component loosening requiring revision; Two failures were (3.5%) due to aseptic loosening and one (2%) due to septic loosening. Fifty-four patients had a radiologically stable integration of the components at latest follow-up - survivorship was 94.7%. The results of this multi-center study demonstrate encouraging short and mid-term results for the use of TM augments in the management of Grade 3A and 3B defects, and defects associated with a chronic pelvic discontinuity

Pelvic discontinuity with associated bone loss is a complex challenge in acetabular revision surgery. Reconstruction using ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment. We reviewed a consecutive series of 26 cases of acetabular revision reconstructions in 24 patients with pelvic discontinuity who had been treated by the component-cage technique. The mean follow-up was 44.6 months (24 to 68). Failure was defined as migration of a component of > 5 mm. In 23 hips (88.5%) there was no clinical or radiological evidence of loosening at the last follow-up. The mean Harris hip score improved significantly from 46.6 points (29.5 to 68.5) to 76.6 points (55.5 to 92.0) at two years (p < 0.001). In three hips (11.5%) the construct had migrated at one year after operation. The complications included two dislocations, one infection and one partial palsy of the peroneal nerve. Our findings indicate that treatment of pelvic discontinuity using the component-cage construct is a reliable option

Aim: We present the surgical technique and early functional and radiological results of cementless acetabular reconstruction with Monoblock Trabecular Metal (MTM) (Zimmer Warsaw, Indiana) cups in patients with Developmental Dysplasia of the Hip (DDH). Materials and Methods: From 1997 to 2004, 70 hips (57 patients) with DDH were received an MTM acetabular component. There where 7 men and 49 women. Average age was 50 years (range 35 to 77). According to the classification of Hartofilakidis et al there where 14 hips with high dislocation, 15 with low type I, 16 with low type II, 8 with low type III dislocation and 17 with hip dysplasia. In all patients a MTM cup was implanted in the true acetabulum through a standard posterior approach. Morselized graft was used in 6 cases and a structural graft only in one. Diameter of the cup was ranging from 42 to 56 mm with 54 out of 70 cups being smaller than 50 mm. Screws where used in 12 out of 70 cases A femoral shortening osteotomy was utilized in only two high dislocation cases. All patients where followed up prospectively and evaluated clinically and radiologicaly at three, six months at one year and yearly thereafter. The clinical outcome was assessed with the Harris Hip score (HHS) and Oxford Score (OS). Results: Average follow up was 50 months (range 103 to 24). There were no revisions for aseptic loosening, radiologic loosening or cup migration during last evaluation. Two patients developed non-progressive radiolucencies in zone one. There were four dislocations in this group. One required open reduction and head replacement while another one needed cup revision due to mal orientation. There were five femoral fractures treated intraoperatively with wires, two patients developed transient sciatic nerve palsy and two non fatal PE. Harris Hip Score was 91 (range 69 to 97) compared with 48 (range 24 to 58) before surgery. The outcome was excellent in 59 hips, very good in 8, good in two and fair in one. Leg length discrepancy more than 2 cm was evident in five unilateral cases (range 2 to 4.5). Trendelebourgh sign was evident in four patients. Conclusion: MTM acetabular component achieved adequate initial stability in this demanding group of patients and they have excellent radiological and clinical results. Posterior approach without femoral osteotomy provided adequate exposure in almost all cases

Reconstruction of an acetabulum following severe bone loss can be challenging. The aim of this study was to determine the outcome of acetabular reconstruction performed using trabecular metal shell for severe bone loss. Between June 2003 and June 2006 a total of 29 patients with significant acetabular bone stock deficiency underwent revisions using trabacular metal shell. According to Paprosky classification, there were 18 patients with grade IIIA and 11 patients with grade IIIB defects. Nineteen patients required augments to supplement the defects. Functional clinical outcomes were measured by WOMAC and Oxford hip. Detailed radiological assessments were also made. At most recent follow up (average 5.5 years, range 3.5–8.5) the mean Oxford hip score improved from 12 preoperatively to 27.11 postoperatively and WOMAC score from 17.57 preoperatively to 34.14 postoperatively The osseointegration was 83% according to Moore's classification. There were two reoperations; one was for instability, and one for aseptic loosening. One patient has a chronic infection and one had a periprosthetic fracture, both treated conservatively. Despite challenges faced with severe preoperative acetabular defects the early results using this technique in Grade III A and B is encouraging

Purpose: Pelvic discontinuity associated with bone loss is a complex challenge in acetabular revision surgery. Reconstruction with anti protrusion cages, Trabecular Metal (Zimmer, Warsaw, Indiana) cups and morselized bone (Cup-Cage) constructs is a relatively new technique used by the authors for the past 6 years. The purpose of the study was to examine the clinical outcome of these patients. Method: Thirty-two consecutive acetabular revision reconstructions in 30 patients with pelvic discontinuity and bone loss treated by cup cage technique between January 2003 and September 2007 were reviewed. Average clinical and radiological follow up was 38.5 ± 19 months (range 12 – 68, median 34.5). Failure was defined as component migration > 5mm. Results: In 29 (90.6%) patients there was no clinical or radiographic evidence indicative of loosening at latest follow up. Harris Hip Scores improved significantly (p< 0.001) from 46.6 ± 10.4 to 78.7 ± 10.4 at 2 year follow up. In 3 patients the construct migrated at 1 year post surgery. One construct was revised to anti protrusion cage with a structural graft while the other was revised to a large Trabecular Metal cup. The third patient is scheduled for revision. Complications included 2 dislocations, 1 infection and 1 partial peroneal nerve palsy. Two patients died due to unrelated reasons at 1 and 3 years post surgery, respectively. Conclusion: Treatment of pelvic discontinuity by Cup-Cage construct is a reliable option based on preliminary results which suggest restoration of the pelvic mechanical stability. However, patients should be followed closely in order to detect cup migration until satisfactory bony ingrowth into the cup takes place

Purpose: Acetabular component revision in the context of large, contained bone defects with less than 50% host-bone-contact traditionally required roof reinforcement or antiprotrusio cages. Trabecular Metal (TM) cups (Zimmer, Warsaw, Indiana) may offer a viable treatment alternative. The objective of this study was to evaluate the clinical and radiological outcome of this mode of treatment. Method: Fifty-four hip revision acetabular arthroplasty procedures performed with TM cups for contained defects offering ≤50% contact with native bone were prospectively followed. Average follow-up was 45 months (range 24–71). All patients were clinically and radiographically evaluated for evidence of loosening or failure. Results: Contact with bleeding host bone ranged from 0 to 50% (average 23%). At latest follow up 43 (79.6%) arthroplasties had excellent or good results, 8 (14.8%) cases had medium or fair results and 3 cases (5.6%) had poor results. Two cups failed and had to be revised. Two additional cups had radiological evidence of probable loosening. Overall preliminary survivorship of the revision acetabulae was 96%. Complications included 4 dislocations and 1 sciatic nerve palsy. Conclusion: Treatment of cavitary defects with less than 50% host-bone contact with using TM cups, without structural support by augments or structural bone grafts, is a viable option

Between November 1997 and December 2000 we performed 27 total hip replacements in 22 patients with high congenital dislocation of the hip using porous tantalum monoblock acetabular components implanted in the true acetabular bed. Clinical and radiological evaluation was performed at regular intervals for a mean of 10.2 years (8.5 to 12). The mean Harris Hip Score improved from 48.3 (15 to 65) pre-operatively to 89.5 (56 to 100) at the final follow-up. The mean Oxford Hip Score was 49.5 (35 to 59) pre-operatively and decreased to 21.2 (12 to 48) at one year and 15.2 (10 to 28) at final follow-up. Migration of the acetabular component was assessed with the EBRA software system. There was a mean migration of 0.68 mm (0.49 to 0.8) in the first year and a mean 0.89 mm (0.6 to 0.98) in the second year, after excluding one initial excessive migration. No revision was necessary for any reason, no acetabular component became loose, and no radiolucent lines were observed at the final follow-up.

The porous tantalum monoblock acetabular component is an implant offering adequate initial stability in conjunction with a modulus of elasticity and porosity close to that of cancellous bone. It favours bone ingrowth, leading to good mid-term results.